Generates the chart image, and returns the contents. This method internally uses LWP::UserAgent. If you want to customize LWP settings, create an instance of LWP::UserAgent and pass it in the constructor

We don't believe that we fully utilize Google Chart's abilities. So there might be things missing, things that should be changed for easier use. If you find any such case, PLEASE LET US KNOW! Suggestions are welcome, but code snippets, pseudocode, or even better, test cases, are most welcome.